Jolting mechanism for foundry apparatus



Sept. 6, 1966 L. c. YOUNG 3,270,375

JOLTING MECHANISM FOR FOUNDRY APPARATUS Filed April 23, 1965 5 Sheets-Sheet 1 50 57 E II E 11 0 54 i -35 3% 4/ I K 30 5 H \l INVENTOR.

LESTER C. YOU/V6 Sept. 6, 1966 1.. c. YOUNG 3,270,375

JQLTING MECHANISM FOR FOUNDRY APPARATUS Filed April 25, 1965 5 Sheets-Sheet 2 Kw mu mm 4 W0. R m m g F M m J M /W 9/ a M w 5 \FHHQ p 6, 1966 L. YOUNG 3,270,375

JOL'IING MECHANISM FOR FOUNDRY APPARATUS Filed April 23, 1965 5 Sheets-Sheet 3 J J HiLl i LLllJ/1 L F/ 5 1 N VENTOR.

LESTER C. YOUNG BY MMMM +1 m5 3 w Sept. 6, 1966 1.. c. YOUNG JOLTING MECHANISM FOR FOUNDRY APPARATUS Filed April 23, 1965 5 Sheets-Sheet 4 INVENTOR.

LESTER 6. YOUNG (un s.

p 5, 6 L. c. YOUNG 3,270,375

JOLTING MECHANISM FOR FOUNDRY APPARATUS Filed April 23, 1965 5 Sheets-Sheet 5 INVENTOR.

LESTER C. YOUNG United States Patent l 3,270,375 JGLTING MECHANISM FOR FOUNDRY APPARATUS Lester C. Young, Cleveland, Ohio, assignor to Spo Incorporated, a corporation of (Dhio Filed Apr. 23, 1965, Ser. No. 450,351 13 Claims. (Cl. 22-45) The present invention relates in general to foundry apparatus and more particularly to such apparatus for compacting molding sand or other material.

In conventional apparatus for performing the jolt method of compacting sand or similar material, the table is raised a predetermined distance above the base anvil, and the lifting fluid is exhausted from the fluid lifting chamber, which permits the jolt table to fall by gravity and strike the base anvil for producing a jolting or table impact operation to aid in compacting the molding sand or other material in the molding flask or other container.

The jolting method of imparting an impact blow to the table has proved advantageous in effectively compacting sand against different surfaces of a table supported pattern, however, the resultant shock transmitted to the supporting means has proven objectionable as the machine must be of heavy construction and provision for a massive foundation is required.

Fluid consumption becomes a factor and as heavy loads are imposed, the jolt piston must be sized to lift the entire dead load including the heavy table.

Frequency of jolt blows per second in the jolting apparatus is usually limited to table up and gravity return stroke, and ranges approximately 120 to 200 strokes per minute.

The object of my invention is to impart a jolt impact blow (sometimes referred to hereinafter as a rapper impact blow) to the table to accomplish the compacting of sand against a pattern surface without imparting any reaction blows to the machine 'base or table supporting means. 4

Another object of the present invention is to provide an apparatus for imparting a series of rapid impact blows to a foundry device which includes gas under pressure to initiate movement of a rapper member in a first direction in combination with the compression of gas under pressure tending to resist movement of the rapper member in the one direction and after the rapper member has traveled a given distance in the one direction, the gas under pressure urging it in this one direction is exhausted and the other compressed gas urges the rapper member in another opposite direction which rapper member strikes a table or other support member to impart an impact blow thereto.

Another object of the present invention is to provide a construction for imparting a series of rapid impact blows to a table member which construction conveniently enables the impact blows to be struck at any conveniently desired position near the periphery of the table as distinguished from only in the central portion or on the center line of the table.

Another object of the present invention is to provide a construction for imparting a series of rapid impact blows to a foundry device by means of a rapper construction whereby the rapper member is driven in one direction by gas under pressure and is driven in the other direction by a gas under pressure which has been further compressed by the movement of the rapper member in the first direction.

Another object of the present invention is to provide a rapper construction whereby on the order of 600 to 720 impacts or raps per minute can be obtained.

Other objects and a fuller understanding of this invention may be had by referring to the following description 3,27%,375 Patented Sept. 6, 1968 and claims, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is an elevational view partially in section of a foundry apparatus constructed in accordance with the teachings of the present invention;

FIGURE 2 is a plan view of the apparatus shown in FIGURE 1;

FIGURE 3 is a fragmentary elevational view of a portion of the device shown in FIGURE 1, however, showing the parts in different position;

FIGURE 4 is an elevational view in section of a modified form of the invention;

FIGURE 5 is an elevational view in section of another modification of the invention;

FIGURE 6 is a still further modification of the teachings of the present invention; and,

FIGURE 7 is an elevational view in section of the elements of the present invention and shown generally inverted as compared to the device of FIGURE 1 with the supporting means shown somewhat schematically.

FIGURE 1 illustrates the teachings of the present invention as incorporated in a foundry apparatus 1t) and this apparatus includes a table member 12 with a generally flat or planar surface 13. A stem 15 is integrally connected to the table member 12 at its upper end thereof and extends away from the table member in a direction which is generally normal to the flat surface 13. The stem 15 is provided with an axially extending bore 17 and this here serves to slidably receive a cylindrical support 19 which extends vertically downwardly and is connected to a base portion 20. First and second springs 22 and 23 are located between the top of cylindrical support 19 and the table member 12 and are used only to resiliently support the dead weight mass of the table and whatever load might be carried on the surface of the table to enable the table and the load to react more effectively from the series of rapper impact blows which are to be transmitted to the table and which will be described in more detail hereinafter.

The stem 15 is seen in FIGURE 1 has an outer surface 26 and the outer surface at the upper end thereof is of a first diameter and a retainer 28 is secured by bolts 29 to the lower end of the stem 15 and this retainer 28 has an outer surface 30 of the same diameter as the surface 26. Intermediate the surfaces 26 and 30 is provided another surface 32 of a smaller diameter. The surface 32 in combination with the retainer 28 and the upper end of the stem acts in effect as an external type of cylinder, the function of which will be further described.

An annular rapper member 35 surrounds the stem 15 and as will be noted in FIGURE 1, has an inner surface which slidably resides on the surfaces 26 and 30. A shoulder 37 or what might otherwise be referred to as an annular projection, extends from the inner wall of the rapper member and engages the intermediate surface 32 on the outside of the stem 15. The shoulder 37, the inner surface of the rapper member, along with the upper portion of the stem, surface 32, and retainer 28, serve to form to define first and second chambers 40 and 41 respectively.

First port means are provided for introducing air or other appropriate gas under pressure from a pressure source 44 into the first chamber ll] in a first position which is the position shown in FIGURE 1. The pressure source 44 includes a valve 45 and a throttle valve 46. The first port means includes passages 47, 48 and 49 and ports 50, 51 and 52. The introduction of air under pressure into chamber 40 from the pressure source 44 causes the rapper member 35 to move downwardly from the first position of FIGURE 1 to the second position shown in FIGURE 3.

Second port means in the form of an opening or port 9 54 in the wall of the rapper member is provided and when the rapper member arrives at this position, fluid under pressure is exhausted. Fluid under pressure is cut off from the pressure source 44 to the first chamber 40 as soon as ports t) and 51 are moved out of alignment with each other.

Third port means in the nature of passages 56 and 57 and port 58 serve to introduce air or gas under pressure to the second chamber 41 from another pressure source 60 which includes a valve 61, adjustable pressure reducer valve 62, and adjustable speed control valve 63. This pressure source 60 therefore provides the second chamber 41 with a given pressure of air.

It will therefore be seen that as the rapper member moves from the position shown in FIGURE 1 to the position shown in FIGURE 3, the volume of the second chamber is rapidly reduced with resultant further compression of the air in this chamber and when pressure is exhausted from the first chamber 40, the movement of the rapper member is stopped and reversed resulting in a thrusting of the rapper member back toward the position of FIGURE 1, and the portion 65 of the rapper member imparts a sharp impact blow to the underneath side of the table 12. As soon as the impact has been imparted to the table, the cycle is rapidly repeated at a rate which enables on the order of 600 to 720 impacts per minute to be imparted thereto. To stop the oscillation of the rapper member 35, it is only necessary to turn off the gas under pressure to the first chamber 40 by way of valve 45. Guide pins 67 are carried by the table 12 and are adapted to cooperate with openings 68 in the rapper member to maintain proper alignment between the rapper member and table.

FIGURE 4 is a modified form of the invention shown in FIGURES 1 and 3. In this particular embodiment of the invention there is demonstrated what may be generally referred to as an internal type piston and cylinder arrangement for driving the rapper member through its series of rapid impact blows, as distinguished from the construction shown in FIGURES 1 and 3, which might appropriately be referred to as an external type piston and cylinder arrangement. In either event, however, it will be appreciated by those skilled in the art that each construction is a piston and cylinder arrangement and with both constructions it is possible to impart a series of rapid impact blows to the table at a position on the table which is not on the center line thereof and which may be at any point on the table toward the peripheral edge thereof, by merely changing the relative position of the table member and rapper member which engages the same on the impact blow.

Specifically, the foundry apparatus shown in FIGURE 4 is indicated generally by the reference numeral 71} and includes a base '71 which has a portion which extends upwardly and at its upper portion is provided with a plurality of springs 72 which reside in appropriate sockets contained therein. A table member 74 is supported by the base through the medium of the springs 72 and has a stem 76 which extends away from the table in a direction generally normal to the flat surface 77 thereof. The stem 76 is provided with wall means 79 which define the walls of a cylinder and positioned within the cylinder 79 is a piston 84} which has a portion 81 in the nature of a piston rod which extends out the lower end of the cylinder. The piston 86 and cylinder '79 serve to define first and second chambers 84 and 85 respectively.

An annular rapper member 87 is provided and assumes a cross sectional shape which may be referred to as cupshaped. The rapper member 87 is secured to the portion 81 of the piston by means of a nut 88 and the rapper member has an upper portion 9% which is designed to engage and transmit an impact blow to the table 74.

Air under pressure is transmitted to the first chamber 84 from a pressure source which is not shown but which may be the same as the pressure source 44 shown in FIGURE 1, and the air reaches chamber 84 by means of passages 92, 93, 94 and ports 95 and 96. Air under pressure is transmitted to the second chamber 85 from a pressure source not shown but which may be the same as the pressure source 6th shown in FIGURE 1 and the pressure reaches chamber 35 by way of passages 98, 99 and port 100. An opening or port 162 serves to exhaust fluid under pressure from the first chamber 84 when the piston has reached what maybe referred to as a second position, as distinguished from the first position within which it is shown in FIGURE 4.

Associated with the apparatus of FIGURE 4 is a down squeeze mechanism which includes a support 82 fixedly secured in a given operative position by means not shown and mounted on the support is a down squeeze cylinder 83 containing a piston 86 and a piston rod 89. The lower end of the piston is connected to a squeeze plate 91. A pattern plate 97 is mounted on the surface of the table and carries a pattern 101. A flask 1G3 surrounds the pattern and sand 105 is provided within the flask and is adapted to be firmly compacted about the pattern 181. Air under pressure is adapted to be introduced to appropriate faces of the piston 86 by means of ports 1% and 107.

The operation of this apparatus is essentially similar to the operation shown in the device of FIGURE 1 in that air under pressure is transmitted to the first chamber 84 by way of passages 92, 93, and 94 as well as ports 95 and 96. This causes the piston and rapper member to move downwardly as viewed in FIGURE 4 further compressing the air under pressure contained in chamber 85. After fluid under pressure is cut off from the first chamber by the unregistering of ports 95 and 96 and subsequent exhausting of the chamber 84 by way of port 102, the compressed air of chamber reverses the movement of the piston and rapper member causing the portion of the rapper member to strike a sharp impact blow to the table 74. It will be appreciated that the air pressure supplied to chambers 84 and 85 may vary considerably, but for the sake of example air to chamber 84 (as well as chamber 40 in FIGURE 1) may be on the order of 80 to 100 psi. and the air to chamber 85 (as well as chamber 41 in FIGURE 1) may be on the order of 50 p.s.i. If the pressure in chamber 84 is varied the downward velocity of rapper will likewise be varied and a change in pressure in chamber 35 will vary the return or upward velocity. It will be seen in this embodiment that the rapper member and piston are connected together so in effect a connected portion of the piston strikes the impact or rapper blow. The springs 72 serve only to resiliently support the weight of the table and the flask 103, pattern 101 and sand 1% carried thereby so as to enable the same to react more effectively when the impact blows are transmitted thereto by way of the rapper member. The base 71 and table 74 are maintained in general alignment by guide pins 104. The sand 105 contained within the flask is adapted to be compressed into the flask by means of the squeeze plate 91 which is urged downwardly by the introduction of air pressure through port 1% onto the upper face of piston 86. The rapping action of the rapper member 87 may be accomplished while the squeezing operation is taking place or otherwise as desired.

FIGURE 5 is a further modification of the form which the present invention may take and in this figure it is shown combined with a conventional jolt construction as well as a construction which enables a foundry flask containing sand therein to be squeezed against a squeeze plate. In this embodiment the foundry apparatus is generally referred to by the reference numeral 1% and includes a base which has a portion which extends upwardly and terminates near the upper portion of the apparatus. The inner walls of the base form the walls of a squeeze cylinder and positioned within the cylinder is a squeeze piston 112 which is adapted for movement between upper and lower positions. A pedestal support member 114-is Q.) secured at its lower end to the piston 112 and extends axially upwardly to terminate in an upper end portion 116. Positioned above the apparatus 108 is a squeeze plate 118 which is fixedly located in an operative position with respect to the foundation upon which the apparatus 108 is mounted.

It will be apparent from a review up to this point, that in this particular embodiment the mechanism for imparting the series of sharp impact or rapper blows to the underside of the table as well as the table construction itself is the same as that shown in FIGURE 1. As a result, where the construction is the same as that shown in FIG- URE 1, the same reference numerals have been applied thereto for the sake of not having undue repetition in the present description. The porting and air passages for initiating the movement of rapper member 35 has not been shown herein but is the same as that shown in FIGURES 1 and 3.

A port 120 is provided for introducing air under pressure into the squeeze cylinder on the lower end of the squeeze piston 112 and the purpose of introducing air in this manner is to raise the entire squeeze piston along with the table and rapper mechanism toward the squeeze plate 118. The table is adapted to carry a conventional pattern plate and foundry flask with sand therein (such as that shown in FIGURE 4) and the plate is adapted to come into contact with the sand to push it tightly into the flask and into contact with the pattern carried by the pattern plate.

The embodiment of FIGURE is provided with passages 122, 123 and 124 and ports 125 and 126 for introducing air under pressure into a chamber 128 formed between the upper end 116 of the pedestal support member and the underside of the table. A port 27 is for the exiting of fluid under pressure from the chamber 128. This construction and fluid porting is for the purpose of accomplishing a jolting operation. This is accomplished by introducing air into the chamber 128 which causes the table and the rapper assembly connected thereto to rise vertically until the ports 125 and 126 are out of register with each other thereby shutting off fluid under pressure to chamber 128 and upward movement causes port 127 to he placed in communication with chamber 128 which exhausts the fluid under pressure in this chamber to atmosphere. This causes the table to fall by gravity, striking the same on an upper portion 130 of the squeeze piston 112 imparting an impact blow to the table.

Additionally the rapper member 35 can be operated by introducing air under pressure to both chambers 40 and 41 which causes a series of sharp impact blows to be transmitted to the bottom of the table as described in the detailed description of FIGURE 1. It will thus be seen that with the apparatus of FIGURE 5, the table can be jolted or the squeezing operation can be performed thereon or a combination of these two operations can be accomplished with the rapping procedure.

FIGURE 6 demonstrates an embodiment of the present invention which can be utilized in a position inverted from that heretofore shown in FIGURES 1 through 5. This particular embodiment of the invention has been designed for removing molding sand 132 from a foundry flask 133 after molten metal has been poured and the finished casting removed therefrom. In the embodiment of FIGURE 6 there is shown a frame 135 and at a lower portion of the frame a support member 136 is provided which has an opening 137 which permits the sand to fall through the bottom of the support member when it is removed from the flask. A support member 139 is provided and has its upper end 140 secured to the upper beam of the frame 135 and a cylindrical portion 134 thereof extends vertically downwardly and has attached at its lower end a piston 142.

The construction of the rapper assembly is the same as that shown and described in FIGURES 1, 2, 3 and 5 (also FIGURE 7 to be described) and where the parts are identical, the same reference numerals have been applied thereto and the operation will be very briefly described hereinafter. The air porting also has not been shown but is the same as in FIGURES 1 and 7. In FIGURE 6 the table 12 and stem 15 are provided with a cylindrical bore Within which the piston 142 resides and these elements form chambers 146 and 147. Porting identified by the reference numeral 149 is provided for bringing air under pressure to chamber 146 from a source through suitable control mechanism neither of which have been shown in this embodiment. Porting 150 is provided for bringing similar air under pressure into chamber 147. It will be readily appreciated by those skilled in the art that when air pressure is admitted to chamber 146 the rapper assembly is maintained in the position shown in FIGURE 6 and when this air pressure is reduced or exhausted and air pressure introduced into chamber 147 the rapper assembly is caused to move vertically downwardly with respect to the support member 139. The surface 13 of the table member is provided with a plate 152 suitably secured thereto which plate in turn carries ejection means 153 and when the table member moves downwardly the ejection means 153 engages the sand 132 to push it out of the flask. The ejection force exerted thereon is determined by the air pressure in chamber 147. While this force is being exerted on the sand a series of sharp impact blows can be imparted to the flask to additionally help shake sand out of the flask by actuation of the rapper member 35. The rapper member as described in the embodiment of FIGURES 1 through 3 is actuated in an identical manner with the exception that the raps are imparted in a downward manner as distinguished from an upward manner and this helps knock sand out of the flask. The downward movement of the rapper assembly by manipulation of air pressure in chambers 146 and 147, is

guided relative to the frame 135 by means of guide pins 155 traveling in openings 156.

FIGURE 7 is an illustration of the rapper assembly of the present invention as it may be utilized in a position inverted from that shown in FIGURE 1. In this embodiment the rapper assembly components are indicated by the same reference numerals as used in FIGURE 1 and is shown supported in its inverted position by means of support plates 158 secured to opposite ends of the table 12 and these plates carry rings 159 which are in turn connected to a support ring 160 by means of chains 161. This illustrates how the rapper assembly may be utilized in its inverted position and the ring 160 may be secured to any raising and lowering means to move the face 13 of the rapper table 12 into contact with any object to which a series of sharp impact blows is to be applied. The operation of the rapper member 35 is identical to that described in FIGURE 1.

It will thus be seen that there has been provided an apparatus for imparting a plurality of sharp impact blows of a very high frequency and to a support table or other mechanism at a desired position from the central portion of the table. There has also been shown a unique method of propelling the rapper member in its movement first in one direction by fluid under pressure and then on the return also by fluid under pressure. The present invention is also convenient of construction and extremely reliable in operation.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. Apparatus for imparting a series of rapid blows to a device including a table member, a cylinder member connected to said table member and extending therefrom, a piston member cooperating with said cylinder member and movable between first and second positions with respect thereto, said piston member having a portion engageable with said table member, said cylinder and piston members defining first and second chambers, first port means for introducing gas under pressure into said first chamber in said first position of said piston member :and causing said portion thereof to move away from said table member toward said second position, second port means for exhausting said gas under pressure in said first chamber to atmosphere in said second position of said piston member, third port means for introducing gas under pressure into said second chamber, movement of said piston member from said first to said second position causing further compression of said gas under pressure in said second chamber to a still higher degree and with exhausting of gas under pressure through said second port means said piston member is moved rapidly back toward said first position and said portion thereof imparts a blow to said table member.

2. Foundry apparatus for imparting a series of rapid blows to a foundry device including in combination a table member, an air cylinder member connected to said table member and extending therefrom, an air piston member cooperating with said air cylinder member and movable between first and second positions with respect thereto, said air piston member having a portion engageable with said table member, said air cylinder and piston members defining first and second chambers, first port means for introducing :air under pressure into said first chamber in said first position of said air piston member and causing said portion thereof to move away from said table member toward said second position, second port means for exhausting air under pressure in said first chamber to atmosphere in said second position of said air piston member, thir-d port means for introducing air under pressure into said second chamber, movement of said air piston member from said first to said second position causing further compression of said air under pressure in said second chamber to a still higher degree and with exhausting of air under pressure through said second port means said air piston member is moved rapidly back toward said first position and said portion thereof imparts a blow to said table member.

3. Apparatus for imparting a series of rapid blows to a device including in combination a table member, a central stem connected to said table member and extending therefrom, said stem having first and second end portions, an annular rapper member surrounding said stem and engageable with said table member outside the diameter of said stem, said annular rapper member being movable between first and second positions, wall means between said stem and at least a connected portion of said rapper member defining a piston and cylinder arrangement having first and second chambers, first port means for introducing fluid under pressure into said first chamber in a first position of said rapper member causing same to move away from said table member to a second position, second port means for exhausting fluid under pressure in said first chamber, in a second position of said rapper member, third port means for introducing fluid under pressure into said second chamber, movement of said rapper member from said first to said second position causing further compression of said fluid under pressure in said second chamber to a still higher degree and with exhausting of fluid under pressure through said second port means said rapper member is moved rapidly back toward said first position and imparts a blow to said table member outside the diameter of said stem.

4. Foundry apparatus for imparting a series of rapid blows to a foundry device including in combination a table member with a generally flat surface, a central stem integrally connected to said table member and extending in a direction generally normal to said flat surface, said stem having first and second end portions, an annular rapper member surrounding said stem and engageable with said table member outside the diameter of said stem, said annular rapper member being movable between first and second positions and being guided in its movement by said stem, wall means between said stem and at least a connected portion of said rapper member defining a piston and cylinder arrangement having first and second chambers, first port means for introducing air under pressure into said first chamber in a first position of said rapper member causing same to move away from said table member to a second position, second port means for exhausting air under pressure in said first chamber to atmosphere in a second position of said rapper member, a third port means for introducing air under pressure into said second chamber, movement of said rapper member from said first to said second position causing further compression of said air under pressure in said second chamber to a still higher degree and with exhausting of air under pressure through said second port means said rapper member is moved rapidly back toward said first position and imparts a blow to said table member outside the diameter of said stem.

5. Apparatus for imparting a series of rapid blows to a device including in combination a table member, a stem integrally connected to said table member and extending therefrom, said stem having first and second end portions, wall means on said first and second end portions defining first surfaces of a given diameter, wall means intermediate said first surfaces defining a second surface of a diameter smaller than said given diameter, an annular rapper member surrounding said stem and having an inner surface slidably residing on said first surfaces, a shoulder extending from said inner surface of said rapper member and slidably engaging said second surface and defining first and second chambers with said first and second end portions of said stem respectively, first port means for introducing gas under pressure into said first chamber in a first position of said rapper member causing same to move away from said table member to a second position, second port means for exhausting gas under pressure in said first chamber to atmosphere, third port means for introducing gas under pressure into said second chamber, movement of said rapper member from said first to said second position causing compression of said gas under pressure in said second chamber to a still higher degree and with exhausting of gas under pressure through said second port means said rapper member is moved rapidly back toward said first position and imparts a blow to said table member outside the diameter of said stem.

6. Foundry apparatus for imparting a series of rapid blows to a foundry device including in combination a table member with a generally fiat surface, a stern integrally connected to said table member and extending in a direction generally normal to said fiat surface, said stem having first and second end portions, wall means on said first and second end portions defining first surfaces of a given diameter, wall means intermediate said first surfaces defining a second surface of a diameter smaller than said given diameter, an annular rapper member surrounding said stem and having an inner surface slidably residing on said first surfaces, a shoulder extending gen erally radially from said inner surface of said rapper member and slidably engaging said second surface and defining first and second chambers with said first and second end portions of said stem respectively, first port means for introducing air under pressure into said first chamber in a first position of said rapper member causing same to move away from said table member to a second position, second port means for exhausting air under pressure in said first chamber to atmosphere in a second position of said rapper member, third port means for introducing air under pressure into said second chamber, movement of said rapper member from said first to said second position causing further compression of said air under pressure in said second chamber to a still higher degree and with exhausting of air under pressure through said second port means said rapper member is moved rapidly back toward said first position and imparts a blow to said table member outside the diameter of said stem.

7. Foundry apparatus for imparting a series of rapid blows to a foundry device including in combination a table member, a stem connected to said table member and extending therefrom, wall means within said stem defining a cylinder, a piston within said cylinder defining first and second chambers and having an end portion extending from said cylinder opposite said table member, an annular rapper member surrounding said stem, means connecting said piston and rapper member together, first port means for introducing gas under pressure into said first chamber in a first position of said piston and rapper member causing same to move away from said table member to a second position, second port means for exhausting gas under pressure in said first chamber in a second position of said piston and rapper member, third port means for introducing gas under pressure into said second chamber, movement of said piston and rapper member from said first to said second position causing further compression of said gas under pressure in said second chamber and with exhausting of gas under pressure through said second port means said piston and rapper member are moved rapidly back toward said first position and said rapper member imparts a blow to said table member outside the diameter of said stem.

8. Foundry apparatus for imparting a series of rapid blows to a foundry device including in combination a table member with a generally flat surface, a stem integrally connected to said table member and extending in a direction generally normal to said flat surface, wall means within said stern defining a cylinder, a solid piston Within said cylinder defining first and second chambers and having an end portion extending from said cylinder opposite said table member, an annular rapper member surrounding said stem and having an inner surface slidably residing on the outer surface of said stem, means connecting said piston and rapper member together, first port means for introducing air under pressure into said first chamber in a first position of said piston and rapper member to cause same to move away from said table member to a second position, second port means for exhausting air under pressure in said first chamber to atmosphere in a second position of said piston and rapper member, third port means for introducing air under pressure into said second chamber, movement of said piston and rapper member from said first to said second position causing further compression of said air under pressure in said second chamber and with exhausting of air under pressure through said second port means said piston and rapper member are moved rapidly back toward said first position and said rapper member imparts a blow to said table member outside the diameter of said stem.

9. A foundry machine including in combination a frame, a vertically extending support member having its upper end fixedly secured to said frame, said support member having a piston at its lower end, a table member with a generally flat surface, a central stem integrally connected to said table member and extending in a direction generally normal to said flat surface, said stem having first and second end portions, wall means defining a bore in said stern slidably receiving said support member and terminating in a piston chamber receiving said piston, an annular rapper member surrounding said stern and engageable with said table member outside the diameter of said stem, said annular rapper being movable between first and second positions and being guided in its movement by said stern, wall means between said stem and at least a connected portion of said rapper member defining a piston and cylinder arrangement having first and second chambers, first port means for introducing air under pressure into said first chamber in a first position of said rapper member causing same to move away from said table to a second position, second port means for exhausting air under pressure in said first chamber to atmosphere in a second position of said rapper member, third port means for introducing'air under pressure into said second chamber, movement of said rapper member from said first to said second position causing further compression of said air under pressure in said second chamber and with exhausting of air under pressure through said second port means said rapper member is moved rapidly back toward said first position and imparts a blow to said table member outside the diameter of said stem, port means for introducing air selectively into either end of said piston chamber to control raising and lowering of said table member and stem on said support member.

10. A foundry molding machine including in combination a base, said base extending vertically and having wall means defining a squeeze piston cylinder, a squeeze piston residing in said squeeze piston cylinder and adapted for movement between upper and lower positions therein, a pedestal member having a first end portion secured to the central portion of said squeeze piston and extending vertically generally coaxial with respect to said squeeze piston cylinder, a table member having a generally flat surface, a stem integrally connected to said table member and extending in a direction generally normal to said fiat surface, wall means defining a cylindrically shaped opening in said stern slidably receiving a second end portion of said pedestal member and thereby defining a lifting chamber, first port means for introducing air under pressure to said lifting chamber and when so introduced causing said table member to rise, second port means for exhausting air under pressure from said lifting chamber causing said table member to drop striking said squeeze piston and base to impart a blow thereto, a squeeze plate fixedly mounted above said table member, third port means for introducing air under pressure into said squeeze piston cylinder to raise said squeeze piston and table member toward said squeeze plate and bring foundry euipment adapted to be carried by the table member into engagement with said squeeze plate, said stern having first and second end portions, wall means on said first and second end portions defining first surfaces of a given diameter, wall means intermediate said first surfaces defining a second surface of a diameter smaller than said given diameter, an annular rapper member surrounding said stem and having an inner surface slidably residing on said first surfaces, a shoulder extending generally radially from said inner surface of said rapper member and slidably engaging said second surface and defining first and second chambers with said first and second end portions of said stem respectively, first port means for introducing air under pressure into said first chamber in a first position of said rapper member causing same to move away from said table member to a second position, second port means for exhausting air under pressure in said first chamber to atmosphere, third port means for introducing air under pressure into said second chamber, move ment of said rapper member from said first to said second position causing compression of air under pressure in said second chamber and with exhausting of air under pressure through said second port means said rapper member is moved rapidly back toward said first position and imparts a blow to said table member outside the diameter of said stem.

11. Apparatus for imparting a series of rapid blows to a device including a table member, a cylinder member connected to said table member and extending therefrom, a piston member cooperating with said cylinder member and movable between first and second positions with respect thereto, said piston member having a portion engageable with said table member, said cylinder and piston members defining first and second chambers, first port means for introducing gas under pressure into said first chamber in said first position of said piston member and causing said portion thereof to move away from said table member toward said second position, second port means for exhausting said gas under pressure in said first chamber to atmosphere in said second position of said piston member, third port means for introducing gas under pressure into said second chamber, movement of said piston member from said first to said second position causing exhausting of gas under pressure through said second port means and said piston member is moved rapidly back toward said first position as a result of said gas under pressure in said second chamber and said portion of said piston member imparts a blow to said table member.

12. Apparatus for imparting a series of rapid blows to a device including in combination a table member, a central stem connected to said table member and extending therefrom, said stem having first and second end portions, an annular rapper member surrounding said stem and engageable with said table member outside the diameter of said stem, said annular rapper being movable between first and second positions, Wall means between said stem and at least a connected portion of said rapper member defining a piston and cylinder arrangement having first and second chambers, first port means for introducing fluid under pressure into said first chamber in a first position of said rapper member causing same to move away from said table to a second position, second port means for exhausting fluid under pressure in said first chamber, in a second position of said rapper member, third port means for introducing fluid under pressure into said second chamber, movement of said rapper member from said first to said second position causing exhausting of fluid under pressure through said second port means and said rapper member is moved rapidly back toward said first position as a result of said fluid under pressure in said second chamber and said rapper member imparts a blow to said table member outside the diameter of said stem.

13. Apparatus for imparting a series of rapid blows to a device comprising in combination a table member including a central stem extending therefrom, said stem having first and second end portions, an annular rapper member surrounding said stem and engageable with said table member, said annular rapper member being movable between first and second positions, wall means between said stem and at least a connected portion of said rapper member defining a piston and cylinder arrangement having first and second chambers, first port means for introducing fluid under pressure into said first chamber in a first position of said rapper member thereby causing same to move away from said table member to a second position, second port means for exhausting fluid under pressure in said first chamber in a second position of said rapper member, means in said second chamber for exerting a force on said rapper member to urge same from said second position back toward said table, movement of said rapper member from said first to said second position causing compression of said means in said second chamber With exhausting of fluid under pressure in said first chamber through said second port means whereby said rapper member is moved rapidly back toward said first position and imparts a blow to said table member.

References Cited by the Examiner UNITED STATES PATENTS I. SPENCER OVERHOLSER, Primary Examiner.

p E. MAR, Assistant Examiner. 

1. APPARATUS FOR IMPARTING A SERIES OF RAPID BLOWS TO A DEVICE INCLUDING A TABLE MEMBER, A CYLINDER MEMBER CONNECTED TO SAID TABLE MEMBER AND EXTENDING THEREFROM, A PISTON MEMBER COOPERATING WITH SAID CYLINDER MEMBER AND MOVABLE BETWEEN FIRST AND SECOND POSITIONS WITH RESPECT THERETO, SAID PISTON MEMBER HAVING A PORTION ENGAGEABLE WITH SAID TABLE MEMBER, SAID CYLINDER AND PISTON MEMBERS DEFINING FIRST AND SECOND CHAMBERS, FIRST PORT MEANS FOR INTRODUCING GAS UNDER PRESSURE INTO SAID FIRST CHAMBER IN SAID FIRST POSITION OF SAID PISTON MEMBER AND CAUSING SAID PORTION THEREOF TO MOVE AWAY FROM SAID TABLE MEMBER TOWARD SAID SECOND POSITION, SECOND PORT MEANS FOR EXHAUSTING SAID GAS UNDER PRES- 